Electric exchange system.



A, '1. BROWN ELEUTRiG EXCHANGE SYSTEM. .A'xrmu P111651!) my: 28, 1896.nnxnwnm JULY 1a, 1.10.

hi'PLIU 992 333 Patented May 16, 1911 a sums-exam 1.

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A. T. BROWN. ELECTRIC EXCHANGE SYSTEM. nrmunmx rmzn um 21:, 1896.nnxnwnn JULY 11;, mo.

Patented may 16, 1911.

W555; :EEQE ,r s I M a I l! al MENEEPF rbbb M ATTORNEYQ A, T. BROWN;BLBGTRIG xcuse 51311311. I 1 urnmumn mum nun, 1195. 381111391! 16,1510.7 992,333. rammed May :16, 1911.

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A. T. BROWN. ELECTRIC EXCHANGE SYSTEM. APPLIOATION 21mm um 23, 1995.um'wzn mu 16, um.

Patented May 16, 1911.

WITNESSES .7

fiwmz Q ATTORNEY! A.-T. BROWN. ELECTRIC EXCHANGE SYSTEM.

APPLIUATION "rum MAY 20; 1895. RENEWED J11 Lx.1.s p1o ""PatentdMay 16,1911.

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A. T. BROWN. ELECTRIC BX APPLICATION FILED MAY 28, 1895.

CHANGE SYSTEM.

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monmivs I A. T. BROWN. ELECTRIC EXCHANGE SYSTEM. 7 APPLICATION mun an23, 18 5. nnnwrm JULY 13, 1010.

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A. T. BROW-f?, ELECTRIC EXCHANGE SYSTEM Agnmul'ox rum) In zagmesfnnnnwnn JUL? m, 1010. 992,333. atenfi dl y 16,1911- f a anus-sum a."

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PATENT OFFICE.

ALEXANDER '1'. BROWN, or SYRACUSE, NEW YORK. ASSIGNOR TO WILBERT LBMITH,

TRUSTEE.

ELECTRIC EXCHANGE SYSTE.

Specification of Letters Yatent.

.atcnted May 16, 1911.

To all whom it may concern:

Be it lmown that I, ALnxANonn '1. BROWN.

of Syracuse. in the count of ()nondaga, in the h'tate of New York, haveinyentcd new and useful Improvcments in Electric 1 15: chai'ig'cSits-terns. of wh u the following, taken in connection witl theaccompanying drawing, is a full, clear, and exact descript-ion.

My invention relates to improvements in electric exchange systems forpermitting automatic communication between different circuits aslf'flllpllvllit'. telegraphic. ate" and has for its object then'ruluetion of a simple and practical apparatus fo' aecon'iplishing thedesired result, which is highly effective in operation-and nmzessitalesin its use buta minimum degree of skill and manipulation; and tothis endit consists essentially in the construction. arrangement, and electricconnection of the component parts of the system,-all as hereinafter morefully described and pointed out in the claims.

In describing this invention. reference is had to the accompanying.lrawiug. forming a part'ot' this specification, in which likelette'rsand numerals indicate correspomling parts in all the views.

Figure l is a diagran'nnatic view illustrating the general constructimiand arrangement of an electric excl'iange svstem emlu'idying my*invention. Fig. 2' is an elevation partly in. section, of one of thedetached switching apparatus of the'system, shown in its normalposition. partly in scctioi'i, ofthc switching apparatus -=;.m1i n Fig.2, which is here shown 'in operativepositii'm. jFi {is a detail sectiontaken F 1g. 5 1s a face new res of the s vson: line 4 4, Fig. 3. 01''one of the controlling (levi tem, its lndieators being shown in theirposi tion assmned for cll'ecting the movmnentuif 1' V the same ca lc ofoperation 111 connection the corresponding switching apparatus to .theposition assumed by the switching appavatus in. Fig.3. Fig.6 is a ,faceview of the ((mtrhllnrgdcvwe seen. in Fig. 5. its

indicators being illustrate?! in a ilill'erent position from thatassumed in Fig. 5. Fi

is a horizontal section, taken on line 'T--i, Fig. 5. Fig. 8 is avertical sect on, talv'en on line 8- 8, Fig. 7.. ,Figs. 9 audit) arevertical section-s looking in opposite directions.

lino 11--1l, Fig. 7. Fig. 1:!

Fig.3 is an elevationf l l i l l view of the brushes or terminals of oneof the controlling devices ancl the terminal support for engaging saidbrushes or termi nals shown liagran'nnatically as a flat: plate. Figs.'13 and 1. 1 are detail sections, taken, respectively. on lines 13'l3and 1414,

Fig. 6. Figs. 15 and 16 are detail sections, taken respectively on linesl5-15 and 1(.3--1(3, Figs. 11 and 8; and Fig. 17 is a detail elevationof a part of an index suitable for use with my improved system.

In nvv improved electric exchange system, uleh circuit for whichautomatic connectiol'i is desired is provided with a switching apparatusfor connecting the same with the other ciri-uit.-.=. and a controllingdevice for governing the passage of the currentover the circuit andthereby controlling or effect.- ing the operation ofthe switchingapparatus. Both the switching apparatus and the controlling devicearepreferably of substantially the construction. herein illustrated anddescribed, although either. may be used without the other. providing thesubstituted deviceis eap'alde of effecting the operation .of the.remaining one of said. mechanisms,

-o'l' the switching apparutus and controlling devices as will be pointedout hereinafter; This system although suitable for a small number ofcircuits. is particularly applicable for a large number, and I haveshown the 'switchingapparatus and the controlling devii'es.as otsuitable construct-ion for operation with .900 circuits, but. a lessnumber may he used therewith, and, at .Fig. 1 I have illustrated onlythree switching apparatus and a t-orrespomling number of connectedcircuits. It' requires however, but. sli ht changes in the constructionof the switching apparatus and cmurolling devices to render with asystem having a greater number of circuits than 900.

The separate circuits converge at a cone mon or main station. are eachprovided witlr atv least one suhserihefis station and prefer-v ablvconsist of two line conductors or wires which are so connected by acoinmonconducandcontrolling devices that alnetallic cult is established:between any two connected circuits for securing substantially undisturbd interconnnnn'ieation. The adjacent tor. cross connections, switchingapparatus,

ends of the line conductors or wires of the separate circuits, theirmain or common 0on ductor, and the cross connections are preferably soarranged and the switching apparatus so constructed, that a movableterminal for connecting the corresponding circuit with another circuitis'required to move but a minimum distance. To facilitate this re-- sulteach switching apparatus is provided with a series of terminals thenumber of which is a submultiple, and preferably the square root, of thenumber of the separate circuits. Each switching apparatus is alsopreferably utilized to cooperate with the controlling device of thecircuit connected by said switching apparatus to the circuit leadingtherefrom for insuring absolute secrecy' between the two connectedcircuits. It it obvious however, that each switching apparatus may beprovided withbut a single movable terminal and ma without those featuresten'ing to secure secrecy between the connected circuits. In theoperation of the switching apparatus, I also preferably avail myself ofthe same line conductors .or wires used for communication betweenthecircuits, and thus reduce the expensc of wiring; and when the systemcontains a large number of circuits, I prefer to use both conductors orwires of each circuit for effecting or controlling the operation of therespective switching apparatus. To fa- .cilitate this result theopposite ends of both of the line conductors or wires of the circuitsare connected to the ground either normally or at intervals, although itis obvious, that instead of usirig the round as a conductor additionalwires may be substituted without material departure from this invention.As my present system is particularly applicable for use with a largenumber of circuits some of which will necessarily be comparatively long,I prefer to actuate the switching appa ratus by a suitable motor and tomerely govern the movement of'each switchingapparatus by thecorresponding controlling deylce; but it, is apparent that instead of.llSlIlg a separate motor for eifecting the operation of the switchingapparatus, a magnet may be connected directly to each switchingapparatus for producing this movement.

A A B B CC, represent suitable conductors or wires of a series ofcircuits, converging at a main or common station'l), and provided withsubscribers stations A B G a b 0 automatic switching'apparatus at thestation D connected to the adjacent ends of said conductors; and D amain or common conductor at the station D connected to each of saidswitching apparatus and connected by a conductor orwire D to a suitablesource of electric energy as a dynamo D referably grounded by aconductor or wire I). The'subscribers stations A B C are provided withsuitable telephones or other be constructed communicators A B G, andsignals A B C, which it is unnecessary to herein illustrate or describeas their construction forms no essential feature of this invention; andthese telephones and the magnets of said signals are connected incircuit with conductors or wires A A, B B, C C, which will be referredto in describingthe controlling devices. lhc conductors or wires A B Care provided with fixed contactterminals A B C arranged preferably inparallel at the main or comnion station D, and the switching apparatus ab c are formed with movable tcrnlinalsa c a, b b b, and c (i c; whichcontact with said fixed terminals and are mounted on suitable supports ab a, forming parts of the respec tive switching apparatus a b 0. Thefixed contactterminals tudinally acrossthe paths of all of the movableterminals of the switching apparatus, but it is obvious that eachcircuit ma be provided with a separate fixed termina for each switchingapparatus. Said fixed contact-terminals A B C may cons st of separatedwires or, as illustrated, o; comparatively thin bars separated bysuitable-insulation d. 1

Suitable cross conductors A B C extend from the-fixed contact-terminals.A B C and may connect directly to their respective circuit conductor-s AB -C although in order to aid in insuring secrecy. when two circuits areconnected, these cross conductors. A B C terminate at circuit breakers Al? C which are connected by conductors or wires A B C to said circuitconductors A B G and are operated by the respective switching apparatus,a b c, as presently described. Each switching apparatus is here shown asprovided with a plurality of movable terminals, and consequently eachmov able terminal engages only a limited number of the fixedcontact-terminals, and if desired the first terminal of the seriesengaged by one of the movable terminals may be slightly separated fromthe last terminal of the series engaged by the next adjacent movableterminal, as illustrated at Figs. 2' and'3, although this arrangement isnot essential.

.The number of the movable terminals of each switching apparatuspreferably equals the square root oi the number of the circuits of thesystem, but the number of said movable terminals may be either greateror less than said square root-although it should be.

submultiple of the total number of said circuits. The switchingapparatushereillustrated being designed. for use with 900 electriccircuits,

fixed contact-terminals of thecircuitsare is therefore preferablyprovidedwith 30 movable terminals, and the divided into 30 series-cachcontaining the terminals of 30a ircuits. I have not deemed it necessaryor a ivi'sable to illustrateeither the entire number of fixedcontact-terminals, or a terminal support provided with movableterminals, nit; at Fig. 2 I have shown two entire series of 30 fixedeontatt-termi nals and two mo able terminals (f e-of the switchingapparatus as presently described, suitably separated from each other forengaging the fixed terminals of each of said series. The remaining fixedand movable terminals of my electric ex,- change system are arrangedsimilar to the like terminals previously referred to. and the terminalsupport of each switching apparatus is required to move only as faas anyone of. its movable terminals. It is obvious however that if theswitching apparatus are each provided with a greater or less number ofmovable terminals. that their terminal supports will be required to moreless or greater distance.

The switching apparatus of my exchange system are all of the sameconstruction and in order to simplify the description of this inventionI will specifically describe only the one a. The tcrlninal support a ofsaid apparatus 0. preferably consists of a rccipro eating insulating haor strip formed with cutouts a for receiving the movable termi l nals aa a", &c., which are electrically' conncctedby a suitable conductor as abar or strip a", securtal to said support 0* and conneeted to themovable conductor A. It is desirable that the erminals a" a may moveindependentlyand they are therefore prefer ably secured to the conductor(1 by conducting pivots o and are normally held out of operativeposition against the action of springs a" arranged in the cutouts rc".The. means for holding the movable terminals out of o wrativc positionpreferably consists of pins or rods ,1. moved lcngtlnvise in aperturesor guides in the support a, by a reciprocating rack IL'". presentlydescribed. which is provided with cutouts rt" arranged one in advance ofthe other. for permitting the springs 11 to successively force saidpinsor rods into inoperative position and to slit-res sivcly force themovable terminals (1.. o" (1- into their plane of engagement 'with' the.timid terminals A ll C 'l'bepius or rods 11- preferably engage themovable terminals 0' 11" a". but electricalconnection between said partsis prevented by insulators a.

l be movable terminals/1' o" u" are howcvel electrically conne ted tothe conductor or wire A by the-conductor '11 lived to the support a, andsaid conductor which is n-efm-ahly flexible is fretlo more when thesupport a is advanced to the desired ||nsitiion 'as presently described.

The rack u is preferably a rrangcd at one sidivof the support a and imovable independently thereof in the direction indicated bvmrow 1. Pi 3b a suitable lcc'd rontrolled by an electrically operat d met-ha nismconnected to the circuit leading to the switchin apparatus a. andcomposed of the line cont uctors or wires A A. The terminal support aand the rack o' may be suitably guided in their movement, but thetern'iinal support a is shown as interposed between the rack m and asupporting plate or bar r1, prefcrablv formed of insulating material andarranged in substantially the same plane as the engaging faces of the,tixed contacttern'iinals A B The rack 11" is interposed between theterminal support. ntand cross bars arranged at the outside of said rack.and said cross bars may be provided with guides f d for preventingtransverse movement of the rack a". The support a. is provided withprojecting arms rt'" which engage the opposite faces of the rack a?" andprevent lateral movement of said support, and if desired. a tongue andgroove connection between the adjacent edges of said support and racltzor suitable guide pieces or bars, not necessary to herein illustrate,may be used to prevent lateral movement of the support rt".

The feed for the raclt'u may be of any desirable. construction but itpreferably eonot' a feeding dog a suitable stop as a dog a. a motor Dand suitable connections between the feeding dog and the motor. Thefeeding dog (W is arranged at the outside of thoracic o and is pivotedat ill" to a suitable support a" whlb may be provided with cars it forguiding th rack rd", and is mounted on the main conductor or((JLHXHOIL.(Olltllltlol D consisting preferably of a spindle or pivotalpin. A spring it normally forces the free end of the feeding dog towardthe rack u". but a pin a secured to the support rt 'and movable in aslot If in the feeding dog. normally prevents the engagement of said dogand rack. The pin ,2!) to the support a." with a lost motion at a. pointbcl\\'r lttl1e pivot a and the free end of the dog, and this connectionenablcstbe feeding dog to swing onit's pivot when cngagcd with the rack1/ until the pin It reaches the opposite end of the slot 12, whereuponthe-support (1" holds sa'i dog firmly in engagement with therat-lcr'nnlpre' vent undue feeding thereof. The support o." isreriprocatcd to and fro. as presently described; and each l'orwardu'iovement op crates the dog'rr to feedtbe rack (/"".a single tooth orstep. The stop or dog (1 prevents return movement of the rack t1)" andis preferably mounted on the comluctor )r spindle D and uormallv engagedwith the rack 11" by a suitable spring-a.

' The mot or I)" for operating the feed for the rack o may be-ot a-ny dtsired t'ornn size, and 'constructi n. and the support. I!" m a v"' besuitably connected thereto. in the pref crable form of my invention Lhemotor I) and the slot 1/? connect the feeding dog consists of aconstantly oscillating shaft which isprovided with a lengthwise shoulder(Z and is actuated by any suitable mechanism not necessary to hereinillustrate or describe. The connection between said motor and thesupport a" preferably consists of a movable arm a having'one end pivotedat a to the outer end of the support a and its opposite endmovable'into' engagement with the shoulder (Z As the arm a is en a edwith the shoulder cl, as prmently described, the support a isrocked onthe conductor or spindle D in the direction shown by arrow 2, Figs. 2and 3, against the action of a spring a and operates the feeding dog ato advance the rack a a single tooth. -The spring a then operates toreturn the support a" and gravity is utilized to facilitate saidmovement and to hold the arm a in its normal position, since Ipreferably arrange the terminal support (1* and the rack a in a verticalplane. It is obvious however that if the parts a a are otherwisearranged, a suitable spring may be utilized toreturn the arm a. a

The electrically operated mechanism for connecting the feeding dogsupport with the motor I) may be of any desirable form, size, andconstruction, but it preferably consists of a magnet a in circuit withthe conductor or wire A, and a lever a pivoted to a suit-able supportand having one end connected by a link a to the armature of said magnetand its opposite and engaged with the movable arm at, for forcing thesame into engagement with the shoulder d of the motor I). As will bepresently described, the passage of the current through the magnet a isgoverned by a. suitable com trolling device e, but in order that the operation of the switching apparatus may be positively assured, "asuitable circuit breaker is connected to the line conductor oi wire A inproximity to the switching apparatus a for breakingthe circuit throughsaid conductor at each movement of the rack c and the break in saidcircuit is utilized 'to advance the operating pieces-of the con.-trolling device, presently described, which regulate the operation ofsaid controlling Any suitable circuit breaker may be traicd oncof simpleconstruction consisting of a ternnnal a?" czmnected to a wire a'leading'from the magnet a and detachably engaged with the upper end, ofthe feeding dog support a", which is forn'led of electric conductingmaterial andpormits the passage of thecurrcnt from the terminal a to themain or common conductor D As the feeding do" upport a" is moved z'--onwardly from its normal pos tion for ad:

' vancing the rack a? a single step, theupper end of said support isseparated from the terminal a and the circuit through the line the lineconductor or wire 'A for engaging the arm a with the motor D and therebyeffecting a second advancemovement of the rack a (louse u'ently,; as thebreak in the circuit through t e conductor or wire A, is

dependent upon each movement of the rack a and the movement of theoperating pieces of thecontrolling device e, presently de scribed, whichregulate the operation of said controlling device is dependent upon eachbreak of the circuit through the conductor or wire A, it is obvious thatthe magnet a remains energized for connecting the feedin dog supportwiththe motor D until said parts are connected and the feeding dog su'iportcoinmences its onward movement.

Moreover, no additional current pulsation is passed through theconductor or wire A for operating the switching apparatus ct un til thesupport a is in its normal position and again restores the circuitthrough the line conductor or wire A.

The rack on is moved lengthwise as described until the desired movableterminal of the corresponding support a has been forced into operativeposition, whereupon the rack is connected by any suitable mechanism tosaid support a for moving ,the same lengthwise until said movableterminal engages the desired fixed contact-terminal. Said connectingmechanism preferably consists of a magneto connected in circuit with theline com'luctor or wire A a connecting dog a pivoted to one or both ofthe cars a of the support a? and movable into engagement with the racka, and a stop or dog a for normally holding the connecting dog out ofoperative posit-ion.

The magnet-d may be connected to the grounded math conducttir D anysuitable means, but I have here shown said magnet as connected theretoby a wire a, the feeding dog support a, and conducting springs c a a.interposed between said wireiand support. The Wire a is suitablyconnected to the spring a which is normally engaged,

with the sprin a. The spring a ds suitably secured to the spring aandits free end is engaged by the outer end of thefeeding dog support awhen in its advance position as seen at Fig. 3. tends to moveqout wardlyfrom engagement with the spring a5, Fig. 3, but is normally held inposition for engaging said springa by one of the arms a of the-terminalport (1.. of the terminal support a the spring a supmovcsoutwardly toits inoperative-position and the ircuit through the line conductor orwire A? to the conductor D is broken andgis. not again established untilthe return .130

The spring a Upon the first onward movement 12'5 ei'igaged with the rackat by the spring a venting stoppage of the supportby the port at as soonas the desired moi-able l 5 te'riiiinal support a", previously stated,is

Q, jac e1 it series of fixed feed for the rack 61- to permit theterminal 40 said feed to engage the last movable tcr minal notillustrated of the support a" with hundredth circuit of the system.

effected y any suitable mechanism; v

switchiiig'apparatus a and the corresponding rack and the sppport a totheir norma lposiof said support to its normal position, as

presently described. A spring a is llt'lllZCfl I the terminal support(.L",cnga; cs an operating to force the connecting dog it into engagei Ii'neiit' with the rack ll. and a link 11*" ot 5 conside'able length isinterposed between I the stop do; a and the armature ot the magnet a. Asthe magnet (11 is energized, the stop or dog a is withdrawn fromoperative position and the connecting dog (6 is whereupon the support ais fed to the dc l sired position by said rack. During this inoveii'ientof the support a, the stop or doe; a swings outwardly on its pivot forpre 5 link a.

As previously described. the rack a permits the movable terminals toassume their operative position, connected to the sup- 5 terminal is inoperative position, and moves the support a, from its normal positionuntil said movable terminal is in engagement with the desired fixedcontact-terminal. The.

provided with thirty movable. terminals, which are so arranged that"when one tirst assumes operative position it is separated one step fromthe first teri'ninal of the ad contact-tierniinals. Coi'isequently, toengage the first movable terminal a of'tlie support o with the first oneof the adjacent series of fixed contact terminals, it requires onemovement of the a" to assume its operative position and a secondmovement of said feed. to engage the terminal-a with said fixedeontact-t'erniiiial. It, therefore, requires sixty movements of the lastfixed contact-terininrle12.agcdthercby, and to thus connect the circuitleading from the switching apparatus a to the nine After two circuitshave been connected by the switching apparatus a, it is desirable forthe switching apparatus to again assume its normal osition, and thisresult may be The controlling device are, however, preferably dtisuchconstruction, that. after the desired ci'i mnuilicat-ion through saidconnected cir-' its has been secured, the controlling dothe e operatesto permit the passage of electitle current pulsations through the magnet'21 until'the rack a has passed beyond its position'assumed whenconnecting; the circuitleading from the switching apparatus a with thenine hundredth circuit. This additional movement oftlie rack a whichpreferably consists of two adyances or steps ishutiliz to effectautomatic return of said tion. 'lo permit of this result a shoulder itsecured to said rack, and thus connected to piece a" of suitableconstruction for forcing the stop u." from 0|)tltltlY0 position.,- Theautomatic return by gravity of the support and rocking said stop on theconductor or spindle l until its engaging end is withdrawn from the racka The. operating piece also preferably holds the stop a out,

of operative position. and is therefore provided with a notch a forreceiving a corresponding tooth provided upon said stop. the rack r4assumes its normal position, a suitable shoulder a thereon forces theoperating piece u out ot'operativc position and the stop a again engagedwith said rack by the spring a. y

It is very desirable to secure secret communication between twoconnected circuits and although this result may be effected by i'aripiismeans. i preferably utilize for its accomplishment the siiitchingapparatus of one of said circuits and theeontrolling device of theother. ll" lien a switching apparatus connects its eorres )ondiiigcircuit with another, the terminal su port of said switching); apparatusmoved away from its norma] position and-"breaks the circuit from itsfixed contact-terminal. The currentfor connecting two circuits must bepassed through the fixed terminal of-the called station and thencethrough the line conductor or wire normally connected thereto, and whenthe circuit from the fixed COllttlC-t-tfil: minal of a station isbroken, it is impossible to connect with said circuit.

As will be apparent after the description of the operation of thecontrollingdeviccs of my electric exchange system, the terminal supportof the controlling device of a connccted or called circuit is forcedirom =1ts normal position when the circuits are connected for telephonicor other ,comtiiunicas tion. and thus prevents the'operative connectionof the telephone or other cotnmunieator of an additional circuit seeking.con-

nection with said called circuit. This thus obvious that secretcommunication between two circuits etl'ected by the switching-apparatusof one and the controlling de vice of the other, and, that an additionalcircuit clannot be connected for intercon'ununieation with eitherofsaideonuected cireuits.-

The switching apparatus ofuthe respective circuits of; iny'systeiapreferably operh-te in connection with suitable circuit breakers foraiding in securing the desired secrecy of piece secured to one end ofthe cross conratus uetor A and normally contacted with the conductor a,whichis electrically connected to the movable conductor A iConsequently, when the support a is in its nor-' malposition-the-conductors A? A are connected by said circuit breaker andthe current is free to "pass from the cross conductor A over theconductor A to the line conductor or wire A. soon as the sup-' port amoves from its normal position for connecting one of its movableterminals with the fixed contact-terminal of another circuit, theconductor (r. is disconnected from the circuit breaker A and the circuitfrom the fixed contact-terminal A thrpugh the rrosscondu ctor or wire Ato the line condnctor A is broken, and, even though a circuit should beconnected with said fixed contact-terminal, it would be cut off from commnnication with 'the line conductor or wire As rcviously stated thecontrolling device of t e called circuit operates to prevent theconnection of any additional circuit thereto, but'as the detailconstruction and arrangement of the parts of the controlling devices ofmy systemhavenot yet'been de scribed, the operation of the controllingdevice for eflecting this result will be subsequently pointed out.

As .rev iously stated, the switching appac are of the same constructionas the apparatus a, and at Fig. 1 I have diagrammatically shownmovable'te'rminals b I) b, c c a, terminal supports 6 .0, racks 1) 0vfeedin e' dogs I) 0, stops or dogs I)" 0,

supports 6? 0'. arms 7) c, magnets b 7), a" a, lovers 5? 0", links 1) 60" 0*, terminals '5 b", 0 0, connecting (lQgH b c, stop. dogs 6 0,operating pieces I) 0" and circuit breakers 13 C corresponding tothelikepar-ts a e a a a ac, a". re re ne n n m se se ss n 42 An ,1 theswitching apparatus a.

The switching-apparatus a b c are arranged side by side and the motor Dpreferably extends crosswise thereof as seen by dotted lines atljlg. 1.,in order that it may operate all ofi saida pa -at:us. The conductor Dalso pretera ly extends crosswise of theswitching apparatusa b a andforms both a main or common electric conductor therefor, and a. supportof spindle for the feeding-and stop dogs of their respective feedmechanisms. It is obvious however -that a separate motor may be used foreach switching apparatus and that any other suitable 111811101 commonconductor may be utilized for connecting said switching apparatus.

The circuits leadin B Care provided with controlling devices e f g whichare all of the same construction;

and, in order to additionally sim lify the (lQSCllEtlOIl ofthis'invention, I wil describe only t v V leading from the station A.This control ling device consistsiof a suitable supporting frame e, aseries of fixed brush or ternunals e e e e e, a movable terminal support0'', movable operatlng pieces c e for automatically operating theterminal s u port escapements for controlling t e movement of saidterminal support and operating pieces, and an actuating moving theterminal support.

. The fixed brushes or terminals 'e c e e a are of suitable form, size,and construction, are preferably arranged one alongside of the other andare secured to any desirable support e f, projecting from the rear wallof the frame e. The terminalsupport e is provided with suitableterminals 0" e" e a piece a for '6' c" for engaging the former terminals0 c 6* e e, and in order that rotary motion from the stations I econtrolling device a for the circuit 1 may be uti'liized "or effectingcontact" of said terminals, the support 6' preferably consists of'a drummounted on a spindle c" connccted to-a suitable grounded conductor orwire 6 The terminals e" e" 0 s are electrically connected to thespindle'et in any suitable manner, as by contact, and the terminals e e?0 which may be designated as surface terminals. are insulated from saidspindle.

The controlling device 8 when suitably adjusted preferably operatesautomatically for making connection with a desired circuit and'duringthis operation the terminal, 'support 0 is revolved for varying theengage 'ment of theterminals c c c e 6",? e a n c c" a. The mechanismfor revolving the support of may be of any suitable form,

size, and cousin-union, although itprcfer;

ably consists of a spring, an escapemcnt permitting the operation Intthe: swing, and operating pieces 1' c, a i actuatmg piece 0 and a magneta for opcrating the escapemcnt. As clearly seen at Fig. 1, the lineCOB-J doctors or wires A A tern'iinate at the fixed brushes or terminalsc"; the conductors A A, previously mentioned, respectively connect. thebrushes or terminals 0 c to theline conductor A and the terminal 0 and aconductor or wlre e? connects the-brush 6 5 plzlced. in thede'siredposition, and a tttiitsilile or terminal a to the line conductor A. Asprm'iously stated, the telephones or other con'u'uuuicalors A and themagnets of the signals A are connected in circuit with the conductors or\vires A A, and a MtKHHl magnet and the magnet c are respeitivelyconnected in circuit with the romluctors or \vircs A A for controllii'igthe escapements which govern the advance movement of the operatingpieces 1: e" and the terminal support. 0 The magnet a may he forn'ied ofwire of high resistance as German silver, for reducing the amperage ofthe. current passed through the conductor or wire A when the signals oftwo connected circuits are operated, but I preferably use for suchmrpose a scparzite resistance c connected in circuit with the conductorA"; This resistance 0" usually consists of an electrio lamp which isarranged. in proximity to the telephone or other commanicator A, and isparticularly useful for guiding a subscriber to said telephone n'heudarkness ohscures its locality.

The terminal support is prett "ably so arranged when in its normal orinitial position that the terminals 6 c are in contact, and-a currentfor operating the signal A is thus free to pass from a calling circuitover the conductors or Wires A A to the grounded wire 0 and'in itspassage illumi' nates the electric lamp 0 and one 'z zcs the magnet; ofthe signal A Said current also nergizes the imignet c and tends to morets aii'nature which is conln-i-ted to operate the escapcrmmt tor theterminal support (:1 but as will be afterward explainerh the armature otthe magnet c is prevented from mo'v'eim'nl' at; this time and cannotoperate said cscapement. connnunicator A is arranged in close prox niitv to the controlling device and nornially restrain the actuating picre1- presentlv described from operative position. \Vheu the signal A" isoperated as de: 'rilaah lrv a calling circuit, the subscriber re thetelephone A? fr m its normal p:

.vition amid the actuatim: piece c'" retrrsehu rotates the terminalsupport c" until the surface tertninal c engage-w the fixed brushes orter- .tuinah a e a-and connects the telephone U in metallic circuit withthe line eomhr-tors A A, IJilllfit reverse movement. of the terminalsupport 1 a breaks the normally glrom'uled circuit through-the terminalsc and the conductor c and as pres-aunt?" tliiscribcd,-thereliy'contrtilsthe connection of the telephone to the. line comlmrtors or wires 011 thecallii-ig-circuit.

W'hcn the controlling" device 0 is utilized to o vieratc;the switchingapparatus (L for cotmecting anotl'icr circuit with the conductots A A, tperating pieces e c"; are first "spring for actuatingtheoperating piecesis" --'.l"he telephone or other \iouslj' mentioned. The controllingdevice 0 then operates automatically to effect onward morei'nent of therack c of the switching apparatus a, :tor permitting the desired movableterminal of said 1; paratus to as some its operative positioi',aspreviously (lQSttt'lbUtl; and upon each. advance of said rack, theelrcuit through the conductor A is broken and the armature of the magnet0 is actuated to perinit the ad ance of the operating pieces a a. Themovement of the rack a, and the operating pieces a a con tinues untilthe operating piece (2 reaches its operative position whereupon itpermits a second advance or step of the. terminal support- 0 forconnecting the terminals e c and thereby grounding the line conductor A.This second advance movement of the terminal support 6 is, however,not-eutiicient to disconnect the terminals (2 e and thus break theground connection for the line conductor A as the terminal a is ofconsiderahle length.

Immediately after the second advance or step of the support a, thefeeding dog support a." engages the terminal a and it current. is treeto pass from the main station I) 1 hrough the line conductor A forconnect- 'ing' the rack a of the switching apparatus through comluctorsfixed tern linal e mot able terminal a of the support 6 fixed terminal aconductor 1 to the conductor A, and the current from the mainstati'on Dpasses from the line conductor A through the controlling leide a and theline conductor A to the tnorahle terminal of the switching apparatur inoperative position,

i and thence through the fixed contact-tersignal A.

minal A? of the corner-ted or allied circuit and the normally groundedline conductor leading t'rom' said contact-terminal.' In its passagethrougl'l said li'ne conductors, the

, current energizesthe magnet operates the and energizes and ,operatsthe corresponding magnet and signal of the conwration.

Upon the operation of the signal of the callingcircuit the subscriber ofsaid circuit removes his telephoneor other communicator from its normalposition, whereupon the terminal support of the adjacentcontrollingdevice is reversely moved for connecting said telephone to both of thecorresponding line conductors or wires and breaking the ground from saidcontrolling device. he signals of the connected circuits then ceasetheir operation and the magnet 6 is deenergized whereupon the terminalsupport 0 is permitted to make a fourth advance or step for engaging theterminals 6 a e and connecting the telephone A in circuit with the lineconductors A A The subscribers of the connected circuits are then freeto communicate with each other over a metallic circuit composed of theline conductors or wires of both circuits, since their correspondingconductors are connccted at the main station by the common'or mainconductor D and the switching apparatus a.

After the desired communication has been obtained, the telephones orother communi cators of the connectedcircuits are again returned totheir normal position, thereby causing the reversely moved terminalsupport of the called circuit to assume its normal-position andpermitting a fifth advance or step of the support e for connecting theterminals 6" e". The circuit from the main 'station D is then free topass tl'irough the line conductor A to the grounded conductor a, andconsequently the rack a and the operating pieces e 6 continue to advanceuntil the limit of their movement is reached.- The last advance movementof the rack a is utilized to return,said rack and the terminal supporta* to their normal position and, during the corresponding movement ofthe operating pieces e e, a third operating piece a permits the sixthand last advance or step of the terminal supo rrt e ,'for separating theterminals 0 ,0" and engaging thc terminals e" e. The engagement of theterminals 6 e c e c, e e" e e c e" e thus controls the passage. ofcurrentsfrom the main station I) through the line conductors or wires AA for operating the switching ap' mratus (z and the mint-rolling device6.

'l'hc terminals (1 a c 6" c a are 'n'oiembly mounted on a rcvolnblc drumand automatic mechanism is utilized for effecting their engagement andobviating the liability of any mistake incidental to hand ,op

Raid terminals may be suitably ruHSllm -(Wl lu'iwevor to permit of theirdc:

sired elujagenn-nl' by hand. and indeed in some instan es, the terminalsI! c 0' a 1" will ilt nnnccesmiry. I may also prefer to operatethc'signals of two connected circuits .lgy some other current than theone passing from the main station I) through both line conductors of thecalling circuit and the nor mall y grounded line conductor of the calledcircuit, and in that event, the terminal a may be dis )ensed'with. It isalso bbvious that providing these changes are made in the switchingapparatus a and the terminals of the controlling device 0, it inay beadvisable to somewhat varyjthe ar 'angcmcnt' and engagement of therciiian'nng term nals of sand controlling device. h-Iorcovcr, themagnets e 0 may be connected to the terminal support e -and theoperating pieces a a, so

asto directly effect the movement of said parts instead of operatingescapcments to permit suitable springs to accomplish this result. a o

- As previously outlined, a rotary drum or tern'iinal support, operatingpieces, magnets, an'actuating piece, and escapemcnts are ntilized toeffect the desired engagement of the terminals of the controlling device0. and although said parts may be of any suitable form, size, andconstruction, and may be connected in any desired manner, I will nowproceed to briefly describe their preferable construction andconnections. The drum loose] mounted on thespindle a and is revolverthereon by a spiral spring 11 having its opposite ends secured tosaiddrl'nn 'and spindle, Fig. 15. One ei'ul'of the spindle c isjournaledin the rear wall of the supporting frame (2 and its oppositeend in a gear a having its hub pun'nalcd 1n the supporting wall a of theframe a.

The drum '0 is normally restrained from movement by its escapement whichpreferably consists of a toothed wheel e,-holding dogs 0" c, and rockingarms afor actuating said dogs. The wheel 0*" is pref crably fixed. tothe drum e; the dogs 0 6" are mounted on a suitable pivot 0", and thearmsie are fixed to a. rocking shaft 0"" pro.- vided with an arm 1".()ne of the arms 1' is preferably. utilized as thearmature for themagnet 0 previously referred to. and a suitable spring (1 normallyseparates said armature arm a" from tho-pole pieces of the magnctc.thereby permitting the main escapementdog 0" to rock into engagementwith the adjacent tooth of the wheel 1 for preventing onward movement ofthe support a, and holding the secondary escapenicnt dog 1" out ofengagement with said wheel c". The arms (2 are rocked from their norinalposition by the lcvcr which tensions the main driving spring oi. thecontrolling devicor'. the operating pieces a c 0 and the magnet 1*". andarofrelnrm'd to their normal position by the spring a. VVlu-n the arms1" are moved against the action of lhosnring r the main escape.-

ment dog 1 is forced ontiof operative |)usi-1 lion and the secondarycscapclucnt dog (2 permits a slight onward movement of the sition andthe support continues the bal.

ance of its onnard advance or step, until the dog 1 engages the toothnextadjacent to that previously e1 ,aged thereby.

The operating pieces a c 113 and 14 may be of any desirable form, size,and construction, and are capable of assuming a niu'nber of differentpositions in which they are securely held by any suitable means as asupport or dish a which rotates said era-rating pieces and engages thesame with the, arm 0 for rocking the shaft o ned the arms a and therebyoperating the escapement for the drum 9 to permit the second and thirdadvances or steps tlnareof, Said. operating pieces are preferablysecured to indicators orhands e e which facilitate their adjustment andare preferably pivoted upon the outer endof the spindle a, The free endsof the indicators or hands c e are provided with suitable bea 'ngs 6 inwhich the operating pieces a e are reciprocally movable, and. thesupport or disl c.

is preferably formed wit ra series of aper tures e for receiving theinner ends of said operating pieces. The apertures e are preferablyarranged in a circular series and as the controllingdevice e is designedfor so with a rack a" capable of making 62 steps I preferably use 61apertures. The operatapertures and thus assume 6 0 different positionsbut one of the apertures is prei'erably closed bythe operating piece eIt is chai cos however, that if the 1st and 60th aper tures are suitablyseparatedand the opcrating piece a is interposed between the same, the61st aperture may be dispensed with and the ope 'atingipiece e otherwisesecured to the support or disk'c. In order thin; the operating pieces aa may be readily plac d in the desired position the front; wall of (I oframe a is providedwrith a suitable indicator e consisting'otgraduations normally alined with the apertures a and when the indicatorsor hands c 6? are directly alined with .two of said 'graduations thermcratirn pieces a a" are free to enter the correspoiul-= ing apertureso and are in the desired posii i I 9 able combination for permitting thedesired duatinction between said indicators.

I preferably use numerals for forming the imjlicators for the separatecircuits, and at lfig. 1T I have slmwn a suitable index or sheet H asprovided with coi'nbinathm indicators 1: 7i, 7L2 7i, h if, forrepresenting the respective circuits leading to the stations A B C Thesubscribers for these stations may be John Jones, James Jackson, andJacob Johnson, and the indicators for the circuits leading from saidstations prefer, ably consit of the iiillou ing combinations 1J3, 3-11.At Fin and 5, I have shown the switching ap iuiratus (a and thecontrolling device a in their positions assumedwhen connecting with theline conductors A A the circuit represented by the combination indicator3----l1. Consequently, the movable terminal a? is shown at Fig. 3,

as engaged with the eighth conta(it-terminalseries ene'a ed b themovable terminal a and the contact terniinals engaged by the 30 moi/ableterminals of the switching appa ratus a are preferably numberedconsecutively, it requires eleven advances or steps of the raclt a andthe operating pieces 6 2 to connect the line conductors "A A" with thegrounded conductor of the 68th circuit, which provided with the fixedcontactterininal 8/ (1 and is designated by the combination indicator3-l1. It also requires only sixty advances or steps of said. l't andoperatin pieces to connect the line i nductors it it, with the 900thciriuit designated by the combimition iinlicator 30-60.

The mechanism for moving the operating pieces a c, prefc ably consistsof a spring; o suital'ily connected to the su 'iport or dislc' and. ancscapement for con" oiling; the .nummient of said support or lhe springo pretendily encircles a sleeve (2 that, the spindle and sleeve 0 e mamore simultaneous in one direction, ant independently in the op 'iositedirection. The free end of the spindle e projects beyond the front Wallof th frame 0 and is pro- \idcd with a'lcver 1 which nrnmally arlymounted on a rocking spindle o ranged in its position assumed at Figs. 5and 6.

The lever a is tilted. upwardly after the operating pieces a e aresuitably arranged forcalling a desired circuit, and is then re turned toits normal position. As the lever e is tilted upwardly the arm e"engages the arm e and moves the same against the action of the spring 6until a suitable stop 6* limits the onward movement of the arm 6. Thespring a is thus tensioned and the arm 6* is restrained from returnmovement by the csc apementfor the support or disk 6". The movement ofthe arm a effected by the lever e, is, however, sufficient to completelyrevolve the gear 6 meshing therewith, and thus detachably engage a toothprojecting from said gear-with a movable do a secured to the support ordisk 6 The tooth 6 and the dog 6 are so constructed and arranged, thatthe gear 6 when actuated by the arm 6 is free to move in the samedirection as indicated by arrow 3, Fig. 10, without rotating the supportor disk c,- and is a fterward prevented from returning to its normalposition, ex cept when the escapement for the support or disk 6* permitsthe operating pieces a e to continue their onward increment as cfiectedby the spring a. After the gear a has been completely revolved, asdescribed, and has commenced its returnmovement, the lever 6 isprevented from again revolving said gear in the same direction. as thatindicated by arrow 3, Fig. until the terminal support a has made acomplete revolution. The means for preventing such movement of the geara may be of any desired form, size, and construction, but it preferablyconsists of a pivot'ed stop 6*, which engages the teeth of the gear 0and is forced out of engagement with said gear when the terminal supporta is in its normal position, "by a cam e secured to said terminalsupport,

After the lever e is tilted upwardly as described for tensioning thespring a, it is returned to its'normal position, and this movement ofthe lever e from and to its normal position utilized .to actuate theescapement for the terminal support a and thus permitthe first advanceor step of said support. This result may be accomplished by any.suitable mechanism, but I preferably use the spring 6"" and arms e asecured respectively to the sleeve e, and the spindle e. As the leve'r'eis tilted upwardly the arm 6 engages the arm 6 and rocks theescapemntdogs 6 e in'one direction, and

as the lever c is reverscly tilted said escapement dogs are moved in theopposite direction by the "spring c ,'thus permitting the first advanceor step of the terminal support 0 The arrow iiustdescribed is engaged bya su'iuidle stop when the movable parts of the controllin device c arein their nor- C onsequently, when a calling current is )ttSSGtl throughthe line condu'ctor A for operating the signal A", the magnet c which issimultaneously energized is unable to attract its armature, and the malposition.

escapement for the terminal support a is not actuated to permit anadvance or step of said support; This stop may be of any desirable torm,size, and construction, but it preferably consists of an arm c fixed tothe arm 0 and normally engaged with the arm a, Fig. 10.

The escapenient for controlling the move ment of the operating pieces ee", preferably consists, of a toothed wheel a and escapement dogs 6actuatedby the magnet 6 The wheel e is supported on a shaft providedwith a pinion 0 meshing with gear teeth formed upon the periphery of thesupport or dislr c and the escapement dogs e are of any suitableconstruction capable of permitting successive step by step movements ofthe wheel 6 As here illustrated, the dogs a e resemble the ordinaryescapement dogs of a typewriter carriage, and one dog 6 is fixed to thearmature of the magnet c and the other dog c is pivoted to said armatureAs the magnet is energized, the dog 0 is withdrawn from operativeposition and the wheel c" completes an advance movement or step, and isrestrained from further movement by the dog a The magneto is thendeiinergized and the armaturetherefor is returned to its normal positionby a' suitable spring, thus engaging the dog a with the tooth of thewheel 6, areviously engaged by the dog c As vthe shaft. provided withthe wheel c is geared to the support or disk carrying the operatingpieces a c", said operatiiig pieces are permitted to make an at vanccmovement or step upon each movement or step of the wheel 6 The switchingapparatus a and the controlling device 6 are preferably of ,suchconstruction that their synchronism is, always maintained, but I havedeemed it advisable to so construct said controlling device that theposition of the operating pieces "c a may be adjusted by the subscriber,should the circuit called not correspond to the one represented by theindicators or hands c a.

'This adinstment is effected by securing the toothed eseapcment wheel toasleeve a movablelcngthwise'on the shaft provided with the pinion c forpermitting disengagement of said toothcd'wheel' and the esca ement dog 0A suitable spring a ho (ls the sleeve e in its normal position, and anpcrture 6 in the lower part of the frame a} peri'nits engagement of saidsleeve. The sub scriber isenabled to readily determine when theoperating pieces a e have reached the desired adjustment effectedbydisengaging the wheel 0 from the dog e, as I preferably arran e anindicator or scale 0 upon the outer ace of the support or disk e. Thegraduations of the indlcators e e are preferably similar and when thecontrolling device 6 is in its normal position, correspondinggraduations of both indicators are in ali'nen'ient with each other. Inorder that this adjustmentof the operating pieces of the controllingdevice e may be readily ap parent I have shown the indicators 0 0 atFig. 6 in their osition assumed when the line conductors the circuitrepresented by the combination indicator 2140, and it will be noted thatthe graduation 40 of the indicator e is alined with the graduation 0' ofthe indicator e. '11, upon communicating with the subscriber of thecircuit then connected to the line conductors A A, it should beascertained that the circuit represented by the combination indicator-Zhll was connected to the line conductors A, A, the user of thecontrolling device 0 would then withdraw the toothed escapement wheel cfrom engagement with the dog a, and rotate the support or disk 0 untilthe graduation 41 of the indicator 6"" was alined with the graduation Oof the indicator cF, whereupon the synchronism of the switchingapparatus a and controlling device c would be established, and, upon thereturn of the supportor disk 0 to its normal position the correspondinggraduations of the. indicators 0 e would be aimed with each other.

The actuating piece 12" may beiot' any desirable form, size, andconstruction, and is,

-prefcrably utilized to co. trol the electric connection of thetelephone or communicator of a calling circuit desiring comn'nuucationwiththe station A, and also to permit the terminal sup ort 1- to makeits fifth advance said tcrminal support. communicator A is normallyengaged with oristep fore ccting the return movement of thcswitchingapparatus a after it has been utilized to connect another circuitwithsaid station A 1 The actuating picce r" preferably consists'ofalever suitably ivoted to the frame e, and, in order that tic desiredmovements ot the' terminal support :1 may be effected thereby, it is]')rovided with up--' wardly projecting arms c" c suitably securedthereto. The arm e is utilized to rc-verscly move the terminal support cand is normally arranged directly beneath a proction or tooth a formedor provided upon The telephone or the outer end oi? the actuating picccc' and its Weightdcpresscs said actuating piece against the action of aspring (""3 .vs the l'Cl81')llO]l( is removed. \vl'icu a call is di-IPt'fl'gtll'fiitlifl signal lluzu'iilillllljl piccc -c"isimmediatelyelevated by the spring I I [en a'g'ingtl arm c with the projcction ortooth 1, T and rcvcrscly moving lhc A are connected with terminalsupport against the action of the spring e As previously stated, l'lllSmovement of the 'tGl'lllllltll support connects the telephone A incircuit with the line conconductors A A, and the magnet-c has beende'energized by the renoval of the telephone of the called circuit, theterminal sup-- port a has been permitted to make four advances or stepsfor connecting the telephone A to the line conductors A A and at Fi 9, Ihave shown said terminal support in this position. The telephone A isthen moved from its normal position upon the cessation of the operationof the signal A, and the spring (1 elevates the actuating .piece 0",whereupon the arm 0 engages an arm 6"" projecting from the shaft 1:, androcks the escapcment dogs 0 in one direction After the desiredconnnunication has been obtained through the conductors A A and thecircuit connected therewith, the telephone A is again placed in itsnormal position, and the actuating piece c is depressed against theactionof the spring c". The spring a then moves the spindle a to itsnormal position for rockingthe escapemcnt dogs a a in the oppositedirection, and permitting the terminal support e to make its fifthadvance or step and ground the conductor A. Ihe rack 11" of theswitching device a then continues its onward move-. ment, andafter-{each advance or step thereof, the support or disk is carrying theop-' crating piccescc" c is aluso advanced by the passage of currentpulsations through the magnet a. i

As the support or disk 0 reaches its position immediately preceding itslast ad- 'vanceor step, the operating piece a is in position to engagethe arm 0" projecting 'l'roiu thc spindle (5 During this last advance orstep, the arm 0" '1S rocked upwardly and is innnediatcly permitted to return to its normal position upon the action oi the spring 0"", thuspermitting the last advance or step of the terminal support 0',whereupon. the ground is connected to the conductor A and isdisconnected 'irom the conductor .lt is very desirable that theactuating piece a shall be free to effect an advance movci'nent or stopof the terminal support only when said support is in its position asumed when connecting the line conductors A A1 for passing a currenttherethrough to the signal of the connected circuit. Consequently, thearm 6" is held out of operative position by a shoulder 6" upon saidsupport which is provided with a flattened portion o that permits thearm e to assume its operative position. As the connection of thetelephone'of the calling circuit is dependent upon the removal of thetelephone of the called station from its normal position, it is obviousthat if the, subs'cribcr for said circuit is absent when his signal isoperated the signals of both stations will continue to ring. until thesource of electric energy at the main station for effecting theiroperation is exhausted; To obviate this result I provide the controllingdevice with suitable releasing mechanism which. may consist, asillustrated, of a, piv

' oted lever e having an arm a for forcing the escapcment dogs 6 e fromoperative position and permitting an advance movement or step of theterminal support 6 To permit this movement of the dogse e the end of thearm 5 normally engaged with said dogs is suitably cut away andto preventundue movement of the support 6 a suitable stop arm e on the lever eenters a groove or cutout in said. support, and limits its-movement.This groove or cutout is only alin'ed with the arm e when the terminalsupport 6'' is in its position as sumed for engaging the terminal (2with the fixed brushes or terminals 6 0* and per mitting the passage ota signaling current through the line conductors A A When the terminalsupport 0' is in any other position, the stop arm e engagessaid support6 and prevents the movement of the lever c"? necessary for forcing thedogs e e from operative position. Itz'will also be understood that themovement of the sup port a efi'ected by; the-lever e" is sufficient todisengage the terminals e e 6*, and an gage the terminals e", e, andthat it isimpossible for said support to stop its'advance movement whenthe terminal e". is, engaged with the fixed brushes or terminals 6* eand thuslconnectsthe telephone A to the line conductors A A". -Aspreviously stated, the controlling devices f g are of the'sam'econstructionas the controlling device e, and at Fig. 1 I havediagrammatically shown fixed g, terminal supports f? g", movabletermicorresponding to the-like parts e 1 e 'e e e 1 12 ll 14 15 e10 e17e1B 2D e21 e28 24 The controlling devicese f g are important parts of myimproved electric exchange system, and in order. that they'may bethoroughly understood,- I will now briefly describe the steps of theoperation of the controlling ulevice -e e d the, circuits through e,which forms the armature of t e ma .ma'gnet of the si tion desiring tocommunicate with the sub-' scriber at the station A is fre'to pass overthe conductors or wires A A, the terminals e" e, the spindle e, and theconductor or wire a to the ground, and in its passage energizes theelectric lamp 6, the ma at ofthe signal A, and the magnet e uring thepassage of-said current, thestope? prevents roc'king of the spindle e bthe arm gnet c and would otherwise be attracted there by, andconsequently, said magnet and the spring a do, not operate theescapement dogs 6 e and permit an advance or forward step of thesuppsrt'e Upon the operation of the signal I? by said calling cur rent,the subscriberremoves the telephone A from the actuating piece a,whereupon the spring 6 elevates said actuating piece, and

the arm a engages the toothe" upon the terminal support 6 and reverselymoves said, support against the action of the spring a, thereby engagingthe surface terminal e with the fixed brushes or terminals :2 6.

This reverse movement oftthe terminalsufiport deie'nergizes the magnetof the ca ing circuit which corresponds to the magnet c of the device e,and the terminal su port of the calling station is then automaticallyoperated to connect the telephone of said calling station in metalliccircuit'witl1.the line'conductors or wires leadingltherefrom.

As the'actuating piece e is elevated, the arm 6 carried thereby is alsoelevated but t-heishoulder 6 upon the'terminalsupport e -holds said armout of its position assumed when about .to engage the arm e"as ,-pres'-ently described. Whrrthe terminals" "e e are connected, a talkingcurrent is i e; 0 pass over the conductors or wires lice? terminals e"e" e, and {the conductor orcwire A to the telephoxieQA? and thence-overthe conductor orwire A -to the line conductor or wire A As soon astheconversation is finished,-the subscriber replaces his telephone A?upon the actuating piece e1. and the mitting the passage of a callingcurrent from the line conductor or wire A through the al A to the groundas previouslypointe out.

The controlling device e1 may be utilized to operatethe switchingapparatus alfor cone nceting another circuit with he;-=condu cliors A A.In that event, the ind' ators or-hands e?" c are rocked on the spindle,e to-the desired position fon'permittingfthe operating pieces e e? t oenter theaperturesc in the support or dlSk cf" v corresponding to thecircuit 'to begconnected to the conductors A A. The lever e" isthgnntjltedjirpivvardly spring e" automatically returns the termi-'nall'support e" to its normal position for per?

